Machine for profiling annular workpieces by rolling



Dec. 30, 1969 J, MARCO'VIT CH MACHINEF'OR PROFILING ANNULAR WORKPIECES.BY ROLLING Filed April 5, 1968 3 Sheets-Sheet l (/9005 Mama/47:

6y JM D 9 J. MARCOVITCH MACHINE FOR PROFILING. ANNULAR WORKPIECESBY.ROLLING Filed April 5, 1968 5 Sheets-Sheet 2 Dec. 30, 1969 J. MARcvncH I I 3,486,358

MACHINE FOR PROFILING AN NULAR WORKPIECES BY ROLLING Filed April 3, 1968r 3 Sheets-Sheet 5 JACOB Me /wow 70,4

Arr-y United States Patent Ofi ice 3,486,358 PatentedDec. 30, 19693,486,358 MACHINE FOR PROFILING ANNULAR WORKPIECES BY ROLLING JacobMarcovitch, Johannesburg, Transvaal, Republic of South Africa, assignorto Rotary Profile Anstalt, Vaduz, Liechtenstein Filed Apr. 3, 1968, Ser.No. 718,402 Claims priority, application Republic of South Africa, Apr.19, 1967, 67/2,272 Int. Cl. B21d 53/16; B21h 1/06 US. C]. 72-91 ClaimsABSTRACT OF THE DISCLOSURE A machine for profiling rings in which amandrel is threaded loosely through the ring and inserted into aconverging throat defined by the surfaces of two or more rollers, andpasses through the throat. The throat runs along the lengths of therollers, at least one of which is helically scrolled to provide a trackto guide the mandrel and workpiece through the machine. The ends of themandrel roll on at least one roller, and the outer face of the workpiecerolls on at least one other roller.

This invention relates to the profiling of annular workpieces byrolling. The workpiece is threaded loosely on to a mandrel which issupported at its ends and which bears on the inner face of theworkpiece. The outer face of the workpiece bears on a roller. Relativerotation of the roller and mandrel causes the workpiece to beprogressively squeezed about its circumference as it works its way,segment by segment, through the space between the mandrel and roller.The mandrel or the roller, or both, are profiled to impose acomplemental profile on the workpiece. Sometimes the workpiece issurrounded by a control ring which limits its diametral spread andprescribes its outer profile.

Many machines exist which allow the above-described operation to becarried out. In particular, the known machines fall into what may becalled two-roller systems and three-roller systems.

In the conventional two-roller systems, the mandrel provides one of therollers, the roller bearing on the outer face of the workpiece providingthe second. The mandrel is mounted in bearings.

In the conventional three-roller systems, the workpiece and mandrel areconfined in a space defined by the surfaces of three rollers, the endsof the mandrel roll ing on two of the rollers and the outer face of theworkpiece bearing on the third.

In both these systems, extensive deformation of the workpiece can onlybe achieved if the axes of the rollers are movable over a considerabledistance relative to each other. This means the machine must have amechanism to regulate the relative movement of the axes of the rollers,so adding to the complexity and hence the cost of the machine, as alsoof its operation and maintenance. Moreover, the production rate islimited because each profiling operation is accompanied by an advanceand withdrawal of the rollers relatively to each other as the workpieceis loaded, profiled and then unloaded.

A variant on the two-roller system has been proposed in the form of asystem in which the mandrel is not a fixture in the machine but advanceswith the workpiece through a space defined between two rollers, one ofwhich bears on the outer face of the workpiece, the second supportingthe ends of the mandrel. The workpiece moves transversely to the axes ofthe rollers. The amount of deformation imposed on the workpiece isdictated by the size and curvature of the rollers. In a development ofthis system, the maximum deformation possible is increased bysuperimposing on the natural convergence of the profiling space arelative movement of the rollers to narrow the space after the workpiecehas been nipped in it. In this modification there must again be amechanism to regulate the movement of the roller axes; and theproduction rate is also low.

Numerous machines exist for profiling solid workpiecesfor instancemaking ballsby passing a solid workpiece such as a rod into and along aconvergent throat defined by the surfaces of at least two rollers, theworkpiece rotating about its axis and simultaneously advancing in thedirection of its axis. The direction of advance of the workpiece isalong the lengths of the rollers. If the rollers are of generallyconstant diameter, they are arranged with their axes slightly convergentto provide the convergence in the throat. If the rollers are tapered,their axes may be parall l. In either case, the roller axes are fixed.The workpiece is profiled--for in stance cut into lengths that are eachdeformed to form a ba1l-by contact with helical scrolls or similarformations on the surfaces of the rollers. This arrangement has theadvantage that the feed to the machine can be continuous, and nomechanism is necessary to advance or withdraw the axes of the rollersrelatively to each other as the operation proceeds. Thus productionrates can be high, and the machine is relatively inexpensive to buildand operate (apart from the cost of the rollers, which may be difiicultto make). However, machines of this system clearly cannot profileannular workpieces, unless they are supported internally by atight-fitting mandrel.

The object of this invention is to provide a machine for the profilingof annular workpieces which allows extensive deformation to be carriedout at high production rates.

A more particular object is to provide a rolling machine for profilingannuli in which extensive deformation can be carried out withoutrelatively moving the roller axes, and through which workpieces can bepassed in rapid succession while the machine is running at full speed.

Accordingly the invention provides, in a machine for profiling annularworkpieces comprising at least two rollers with juxtaposed surfacesdefining a convergent throat which extends in the direction of thelengths of the rollers, at least one of the rollers being rotatableabout its axis, formations on the roller surfaces to squeeze a workpiecelocated in the throat and cause it to be profiled, and means to rotateat least one roller about its axis to impose rotation on the workpiece;the improvement of a mandrel adapted to be threaded loosely through theworkpiece with its ends projecting from the workpiece, the outer face ofthe workpiece being adapted to roll on the formation of at least one ofthe rollers while the workpiece rotates and simultaneously advancesalong the throat, the formation on at least one other roller being landson which the ends of the mandrel are adapted to roll while the mandreladvances with the workpiece along the throat.

If two rollers are provided, they may be rotated at different peripheralspeeds so that a workpiece and mandrel inserted into the machine at oneside of the plane defined by the roller axes will emerge from themachine at the other side of that plane. In other words, the workpiecewill have a component of motion at right angles to its direction ofadvance along the throat. This additional component will enhance thedeformation which can be achieved as a result of the convergence of thethroat. The rollers may be mounted with convex surfaces facing eachother to define the throat, or one may be hollow with the second locatedeccentrically within it. There can also be a two-roller arrangement inwhich one roller is mounted eccentrically within another, in which casethe throat is annular.

With a three-roller system, the workpiece is entrapped in the spacebetween the roller surfaces and it will normally advance rectilinearlyalong the throat. All three rollers rotate at the same peripheral speedat any point along the length of the throat.

The profiling formation on the rollers will generally be a scrollextending helically round the rollers. The scroll may be salient orrecessed. In some cases the formations can he plain cylindricalsurfaces, providing a track for the workpiece or mandrel.

Various embodiments of the invention are described below with referenceto the accompanying drawings, in which:

FIGURE 1 is a semi-diagrammatic end view of a machine for profilingannular workpieces, the machine having three juxtaposed rollers;

FIGURE 2 is a side view of two of the rollers of the machine of FIGURE1, the third roller being removed to illustrate the position of theworkpiece and mandrel;

FIGURE 3 is a fragmentary, simplified view of an edge of one of thescrolled rollers of the machine of FIGURES 1 and 2, illustrating themanner in which the mandrel and workpiece and control ring are located;

FIGURE 4 is a fragmentary view of one form of plain roller for use inthe machine of FIGURES 1 to 3;

FIGURE 5 is a semi-diagrammatic end view of a tworoller machine forprofiling annular workpieces;

FIGURE 6 is a side view of a scrolled roller which might be used in themachine of FIGURE 5, a mandrel and workpiece also being shown located onthe roller; and

FIGURE 7 is a semi-diagrammatic side view, partly in section, of anothertwo-roller machine for profiling annular workpieces, one roller beinghollow and the second contained within it.

The machine of FIGURES l and 2 has three rollers 10, 11 and 12juxtaposed to each other to define a throat within which an annularworkpiece 13, threaded over a mandrel 15 and contained within a controlring 14, is profiled. The throat extends along the length of therollers. The rollers rotate about their axes. The rollers and 11 aregeared to each other and driven by means well known in the art and notillustrated. The third roller 12 idles, although it, too, could bedriven.

As seen in FIGURE 2, the rollers 10 and 11 have recessed scrolls intheir surfaces in the form of helical grooves 16. The surfaces 19between the grooves 16 are formations in the form of plain cylindricallands on which the ends 18 of the mandrel roll. The mandrel is thussturdily supported at its ends, and it is kept axially in placerelatively to the rollers 10 and 11 by a head 20 at one of its endswhich protrudes into the grooves 16. The control ring and workpiece alsoextend into the grooves 16, without touching the bottom of the grooves,and are thus held axially in place with respect to the mandrel androllers 10 and 11. The surface of the roller 12 is plain and, as seen inFIGURE 1, it bears on the outer face of the control ring.

The throat defined between the rollers 10, 11 and 12 converges fromright to left in FIGURE 2. The helical grooves 16 are of the same pitchand hand and are in register. An assembly of workpiece, mandrel andcontrol ring is inserted in the throat at the right-hand end when theends of the scrolls, which are single-start, register at that end of themachine. The assembly is then entrained in the throat and drawn throughit as the rollers 10 and 11 are driven in the direction indicated by thearrows in FIGURE 1. The outer face of the control ring bears on theplain roller 12 and drives it frictionally. The assembly advances fromright to left rectilinearly through the throat, as indicated by thearrow in FIGURE 2.

As the assembly advances down the throat, its convergence causescorrespondingly increased squeezing pressure on the workpiece and soimposes the profile of the mandrel and control ring on the inner andouter faces of the workpiece. Ultimately the diameter of the workpiecewill have increased to the point where it is a tight fit in the controlring. The machine will be so operated that, when the assembly hastraversed the throat and emerges at the far end, profiling will becomplete.

Convergence of the throat can be induced by any of several factors, aswell known in the art. If, as illustrated in FIGURE 2 the rollers are ofsubstantially constant diameter (except, of course, where indented bythe grooves 16), they may be mounted in the machine with their axesslightly convergent. Another possibility is illustrated in FIGURE 3.Here the scrolled rollers 10, 11 are stepped along their length, thefinal (left-hand) portion of the roller being of constant diameter sothat a finishing operation akin to burnishing is given to the workpiecein the last stage of the operation. (For clarity of illustration, thescrolls are shown as annular grooves in FIG- URE 3. Equally, asillustrated in FIGURE 4, exag gerated for the sake of clarity, theroller 12 might be of increasing diameter along the length of thethroat. The increase in diameter need not be uniform. For instance, inFIGURE 4, there is a portion A of constant diameter, provided to allowthe assembly of workpiece, mandrel and control ring to be easily loadedinto the machine, followed by a gently rising zone B, a more abruptlyrising Zone C in which the bulk of the deformation is imposed on theworkpiece, a further gently rising zone D, in which deformation reachesor nears its end, and a final zone E of constant diameter in which theburnishing or finishing operation takes place before the assembly isejected.

Another possibility is that, during profiling, one of the rollers ismade to approach the others relatively; for instance the roller 12 mightbe mounted for bodily movement relatively towards the other rollers 10and 11. This arrangement has the disadvantages, however, that amechanism to regulate this movement must be provided, and further thateach workpiece must pass through the full length of the throat beforethe next is introduced into it, so slowing up the production rate, Ifthe roller axes are fixed and convergence is provided by other means,one assembly can be inserted in the machine on each revolution of therollers; that is, when the ends of the scrolls are in register at theright-hand end of the machine. If the scrolls were double-start, twoassemblies might be inserted into the machine on each revolution, sodoubling the production rate.

It is apparent that the amount of convergence in the throat, andconsequently the extent of deformation imposed on the workpiece, can bevery large.

From FIGURES 2 and 3 it will be seen that the control ring 14 isbevelled at its sides to fit cleanly into the grooves 16 of both rollers10 and 11. This allows the mandrel axis to advance rectilinearly alongthe throat, as shown by the arrow in FIGURE 2.

FIGURES 5 and 6 show a two-roller machine. The rollers 21, 22 arejuxtaposed with a scroll on roller 21. Roller 22 is smooth-surfaced.Convergence of the throat 24 between the rollers along their lengths iseffected by coning the rollers 21, 22 or either of them, or by incliningtheir axes to each other. Both rollers are driven, as shown by arrows.The mandrel 25 rolls on the lands 28 of the roller 21, and the workpiece26, in the control ring 27, is guided and driven by the scroll recessalong the throat and is profiled by pressure against the mandrel and thecontrol ring, or both. If the control ring imposes a profile on theworkpiece, it must always be one that will permit demounting of thefinished workpiece.

In addition to advancing along the length of the rollers, the workpieceis given a component of motion in a direction from one side to the otherof the plane defined by the axes of the rollers. This component isgoverned by adifferential peripheral speed of the rollers 21 and 22. Therollers are arranged and dimensioned to nip the mandrel and theworkpiece, (and the control ring, if one is used on insertion at oneside of the machine, as seen in FIG- URE 5, and to entrain the assemblythrough the throat. The differential peripheral speed, in relation tothe diameter of the workpiece, is so chosen that, during the time takento traverse the full length of the rollers, the workpiece will also passfrom side to side of the plane defined by the roller axes. The resultantdirection of motion of the assembly is shown by the arrow in FIGURE 6.The axis of the mandrel will normally, as seen by the line XX in FIGURE6, not move parallel to the throat 24 but perpendicular to the directionof the scroll. However, if desired, it may be kept parallel to thethroat but the control ring should then be bevelled, as shown in FIG-URES 2 and 3, to permit it clearing the sides of the scroll grooves.

In the machine of FIGURES 5 and 6, it is clear that the amount ofdeformation imposed on the workpiece can be far greater than that whichwould be imposed merely by passing the workpiece from side to side ofthe rollers. Deformation obtained by this transverse passage through thethroat is, as it were, superimposed on that obtained by the translationof the workpiece along the throat.

The main advantage of two-roller systems of the type shown in FIGURES 5and 6 is that a rest or support for the mandrel assembly is unnecessaryduring profiling.

Machines such as are shown in FIGURES 5 and 6 are unbalanced andtherefore must be built massively to withstand unbalanced forces ofgreat magnitude. The machine shown in FIGURE 7 does not suffer from thisdisadvantage. Here, a roller 40 with a recessed scroll 41 is mounted forrotation concentrically in a hollow roller 42. The annular throat 43between the rollers converges, by making the inner roller 40 or theouter roller 42, and preferably the latter, conical. A chute 44 guidesannular workpieces 45 containing mandrels 46 into engagement with thescroll outside the roller 42, the workpiece and a head 47 on the mandrelentering the scroll in adjacent turns. The workpieces may be containedwithin control rings. The workpieces are entrained by the scroll intothe throat and advance through it as the roller rotates. The feed issuch that the workpieces space themselves around the circumference ofthe rollers, and the machine is substantially dynamically balanced. Ahigh throughput is therefore possible without needing a machine that isimpractically massive.

The workpieces fall gravitationally from the end of the scroll and areseparated from the mandrels and from the control rings, if these havebeen used.

The machine of FIGURE 8 has the further advantage that the hollow roller42 can be kept stationary, and only the roller 40 need be driven.

I claim:

1. In a machine for profiling annular workpieces, comprising at leasttwo rollers with juxtaposed surfaces defining a convergent throat whichextends in the direction of the lengths of the rollers, at least one ofthe rollers being rotatable about its axis, formations on the rollersurfaces to squeeze a workpiece located in the throat and cause theworkpiece to be profiled, and means to rotate at least one roller aboutits axis to impose rotation on the workpiece; the improvement of amandrel adapted to be threaded loosely through the workpiece with itsends projecting from the workpiece, the outer face of the workpiecebeing adapted to roll on the formation of at least one of the rollerswhile the workpiece advances along the throat, the formation on at leastone other roller comprising lands on which the ends of the mandrel areadapted to roll while the mandrel advances with the workpiece along thethroat.

2. The machine of claim 1 in which there are two non-concentric rollers;including means to rotate the rollers at different peripheral speeds sothat a workpiece inserted into the machine at one side of the planedefined by the axes of the rollers will emerge from the machine at theother side of that plane.

3. The machine of claim 1 in which there are two concentrically mountedrollers that define an annular throat.

4. The machine of claim 1 in which there are three rollers defining athroat through which the workpiece is adapted to advance substantiallyrectilinearly, the workpiece rolling on the surface of one of therollers and the ends of the mandrel rolling on registering lands on theother two rollers.

5. The machine of claim 1 in which the formation on at least one of therollers is a helical scroll.

6. The machine of claim 5 in which the scroll is recessed.

7. The machine of claim 5 in which the scroll is salient.

S. The machine of claim 1 in which a roller on which the ends of themandrel roll is recessed between the lands to provide a groove toaccommodate the workpiece.

9. The machine of claim 1 in which the axes of the rollers are fixed.

10. The machine of claim 1 including a control ring surrounding theworkpiece and being adapted to roll on a roller on which the outer faceof the workpiece would otherwise roll.

References Cited UNITED STATES PATENTS 1,417,324 5/1922 Holmes 72-1032,060,087 11/1936 Klamp 72-103 3,345,845 10/ 1957 Marcovitch et al. 7291RICHARD J. HERBST, Primary Examiner US. Cl. X.R. 72-96, 104

